I am about 10 years removed from Circuit design so pardon me for being a bit rusty. I have a 6vdc to 40vdc signal that I want to clip at a 0 - 24vdc signal to trigger a relay. This is coming from the auxiliary port on a desk phone and I wanted to convert this into a "line in use" light. If I can get the voltage down I can connect to a relay and then I 'm good from there. I however am confused which direction to go and which components to pick. If I can get started on the right path I should be ok, if anyone can give a few suggestions.